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The world's best gem articles, published weekly.

Most Recent Articles

Product Review: No Name Refractometers

Beware of cheap “no name” refractometers (and their distributors). These tools may not be suitable for gem identification. Read our review to learn more.

What are Jeweler’s Bench Pins?

Jewelry makers use bench pins to steady their hands, tools, and pieces for intricate work. Learn which type of bench pin will best meet your needs.

Scorodite Value, Price, and Jewelry Information

With lovely colors and intense pleochroism, faceted scorodite is a prize for collectors of the rare and unusual. However, it’s too soft for jewelry use.

Legrandite Value, Price, and Jewelry Information

Too soft for jewelry use, legrandite is a popular collector’s mineral because of its intense yellow color and aesthetic crystal groupings. Transparent, faceted gems are extremely rare.

Product Review: Duplex II and Rayner Dialdex Refractometers

The Duplex II and Rayner Dialdex both make excellent refractometers for gemologists. How do they compare head-to-head? Learn more from our review.

How to Measure an OTL Gemstone Refractive Index

Measuring “over the limit” (OTL) refractive indices can help distinguish diamonds from simulants. You can do this with a simple upgrade to your microscope.

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"Becoming a Pro Member of IGS just made good sense for my business. The gemology resources are fantastic, and my profile lets potential customers know I am serious about colored gemstones. And frankly, if I get any exposure to potential customers it's a no-brainer."
Paul Bierker, Paul Michael Designs
Jeweler, IGS Pro Member

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Over 15 years, we have assembled detailed pricing and value information for appraising over 70 different gemstones. The values in our guide come from a variety of sources including primary and secondary gemstone dealers, jewelers, miners, and wholesale suppliers of commonly traded gemstones.

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